#include <bits/stdc++.h>

using namespace std;

ifstream fin("apm.in");
ofstream fout("apm.out");

int n,m,t[200003];
struct Muchie
{
    int x,y,cost;
    bool viz;
};
Muchie a[400003];

void Citire()
{
    int i;
    fin>>n>>m;
    for(i=1;i<=m;i++)
        fin>>a[i].x>>a[i].y>>a[i].cost;
}

void Union(int x, int y)
{
    t[y] = x;
}

int Find(int x)
{
    int rad,y;
    rad = x;
    while(t[rad] != 0)
        rad = t[rad];
    while(x != rad)
    {
        y = t[x];
        t[x] = rad;
        x = y;
    }
    return rad;
}

inline bool CMP(Muchie A, Muchie B)
{
    return A.cost < B.cost;
}

void APM()
{
    int i,costmin,nrcc,x,y;
    sort(a+1,a+m+1,CMP);
    nrcc = n;
    costmin = 0;
    for(i=1;i<=m && nrcc>1;i++)
    {
        x = Find(a[i].x);
        y = Find(a[i].y);
        if(x != y)
        {
            a[i].viz = true;
            costmin += a[i].cost;
            Union(x,y);
            nrcc--;
        }
    }
    fout<<costmin<<"\n";
}

void Afisare()
{
    int i,cnt;
    cnt = 0;
    for(i=1;i<=m;i++)
        if(a[i].viz == true)
            cnt++;
    fout<<cnt<<"\n";
    for(i=1;i<=m;i++)
        if(a[i].viz == true)
            fout<<a[i].x<<" "<<a[i].y<<"\n";
}

int main()
{
    Citire();
    APM();
    Afisare();

    fin.close();
    fout.close();
    return 0;
}